We did DSD with my son an year before we got certified. My son was 9 at the time... Yeah, we lied about his age:shocked2: since he was a really tall and strong for 9 (or 10 for that matter) year old kid. We did it on vacation in Puerto Vallarta. Scuba Caribe had a great french guy in our hotel that I think did an outstanding job during our in class and pool session. Looking back I think he went well beyond what you'd expect in DSD class. We even talked and attempted to work on basic trim, etc. Then, on another day, we went on a "cattle boat" to "open water" site with another instructor. There were 3 DSD students per instructor but another lady didn't make it during basic drills (mask clearing while hanging on a line) and bailed out. Two of us had a blast, instructor pointed out all the local creatures. Looking back, viz was just so-so, maybe 40-45 feet. But we had great time. One year later we got certified (when my son turned 10) and, while not "heavy duty", we've been diving ever since. OW was so easy, majority of the drills we would do on a fly without any issues, instructor was pleasantly surprised. I'm still crediting that french guy in Puerto Vallarta for us getting into this and continuing with it.